1. Field of the Invention
The present general inventive concept relates to a hybrid toner for an electrostatic electrophotographic development system and a method of fabricating the same, and more particularly, to a toner having a core-micro cylinder structure in which a core is inserted to a micro cylinder to prevent a toner blocking phenomenon, image contamination, and low storage stability which occur due to dispersion of wax or colorants to an outer surface of the toner, and a method of preparing the same.
2. Description of the Related Art
With respect to electrophotographic techniques or electrostatic recording techniques, developing agents which visualize an electrostatic image or an electrostatic latent image are categorized into 2-component developing agents which consist of a toner and carrier particles and 1-component developing agents which substantially consist of a toner alone, that is, does not use carrier particles. 1-component developing agents can be categorized into magnetic 1-component developing agents which include a magnetic component, and nonmagnetic 1-component developing agents which do not include a magnetic component. In general, a super plasticizer such as colloidal silica is independently added to a nonmagnetic 1-component developing agent to improve flowability of a toner. Generally, coloring particles obtained by dispersing a colorant such as carbon black or other additives in a binding resin are used in the toner.
Toner can be prepared using a pulverizing method or a polymerizing method. In a milling method, a synthesized resin, a colorant, and when required, other additives are melted, milled, and then sorted to obtain particles having desirable diameters, to thereby obtain a toner. However, due to characteristics illustrated when a toner is prepared using a dry milling method, when an amount of a wax is more than about 2.5 wt %, durability and storage stability of the toner may be degraded. Accordingly, the amount of the wax cannot be increased although a large amount of wax is required to prevent an offset phenomenon and improve fixing properties. In addition, when a toner is prepared using a milling method, a wax acting as an inner additive is required to be exposed in the milling process. Such exposing can cause toner blocking, and thus an image obtained from the toner may have defects and storage stability may be decreased.
Meanwhile, when a toner is prepared using a polymerizing method, a colorant, a polymerization initiator, and when required, other additives, such as a crosslinking agent or an antistatic agent, are uniformly dissolved in or dispersed into a polymerization monomer to prepare a polymerization monomer composition. Then, the polymerization monomer composition is dispersed into an aqueous dispersion medium including a dispersion stabilizer using a stirrer to form micro droplet particles of the polymerization monomer composition. Subsequently, the temperature is increased and then a suspension polymerization process is performed to obtain colored polymerization particles having desirable diameters, that is, a polymerization toner. For example, to prepare a toner, a core is formed using a vinyl-based monomer and an initiator, and then a vinyl-based monomer having hydrophilic properties equal to or greater than the core and a glass transition temperature (Tg) higher than the core is polymerized to form a shell. This method, however, requires a shell having a large thickness to obtain a clear core-shell structure and to improve preservation properties.
Specifically, with respect to electrophotographic copying machines, laser beam printers, and electrostatic recording apparatuses, in which images are formed using an electrophotographic technique or an electrostatic recording technique, a toner for developing an electrostatic image requires a low temperature fixing developing agent, corresponding to a high-speed device. Accordingly, there is a need to develop a developing agent which can be fixed at a low temperature.